“Although the cause of the accident in Lac-Megantic remains unknown at this time, Transport Canada is moving forward to build upon the safety advisories received last Friday from the Transportation Safety Board,” Transport Canada said in a statement.

On July 6, a Montreal, Maine & Atlantic Railway train parked overnight at a nearby town slipped away, derailed and exploded, flattening part of the picturesque town of Lac-Megantic and killing 47 people.

The railway’s chairman has said the disaster appeared to have been caused by an engineer’s failure to properly set hand brakes on the train.

The train was carrying crude oil from the Bakken shale fields of North Dakota in 72 tanker cars near the Canada-US border to an Irving Oil refinery in New Brunswick.

Canada’s Transportation Safety Board on Friday urged railways to check the brakes on all trains, after a preliminary investigation into the derailment faulted its brakes.

The board also warned operators not to leave trains unattended or unsecured on main lines, and to review their protocols for transporting dangerous goods.